Air pollution is one of the great problems facing China at present. With the development of Chinese economy, photochemical smog, smog and PM 2.5 (PM is a particulate matter) are becoming more and more serious, which has caused huge influences on daily life and physical health. Air pollution is mainly caused by outdoor and indoor pollutants. Outdoor gas pollutants include respirable particulate matter, nitrogen oxides, sulfur dioxide and carbon monoxide, while indoor air pollutants mainly include formaldehyde, toluene and hydrocarbons. At present, with the rapid increase in the number of automobiles in China, the emission of automobile exhausts has increased the degree of air pollution, and nitrogen oxide is one of the typical gaseous environmental pollutants. With the continuous development and advancement of science, the current methods for treating exhaust gas include activated carbon adsorption method, catalytic combustion method, biological filtration, acid-base neutralization method, etc., but the above methods have the advantages of expensive, difficult to regenerate, and only suit for high concentration exhaust gas, and it is extremely ineffective in treating low concentrations of harmful gases remaining in the air. However, for the treatment of low-concentration exhaust gas, semiconductor photocatalysis is considered to be one of the most promising technologies. Due to its high efficiency and environmental characteristics, semiconductor photocatalysis has potential value in solving global energy shortages. However, the effect of existing treatment agents on the degradation of nitric oxide is far from the expected effect.